From Mike Horn, IFBB Pro Bodybuilder:
"You know I've already done extensive research on cross fit/boot camp "training". First, it's not training it's exercise. There are training principles that were adapted to the routines in an effort to appear as if they do the various Powerlifting lifts - Squat / Bench Press / Deadlift. Olympic lifts like Clean and jerk and Snatch are lifts that require many years to master.
One Olympic lift that was banned by the Olympic Committee was the Clean and Press because it was too difficult to determine proper form. That’s right, all Olympic Lifts and Powerlifting lifts must be judged and under extreme scrutiny to ensure no injuries (Even Military required exercises for testing basic "PFT"). There is a standard that the basic push-up / sit-up / 2 mile run / and pull ups are all tested (with the detrimental emphasis on form)… or they don't count. It's called cheating.
When I went into U.S. Army Airborne Medic I trained like a machine and already shaved my head. I was gung-ho! I did 180 push-ups in 2 minutes. Most of the time resting with my but in the air. After the first minute I busted out 133 and then had to stick my butt in the air because if you go to your knees then it's over. I did close to 200 but didn't get credit for all due to bad form on some. They require a perfect push-up just like all their lifts. And if you cannot perform the basic requirements then you cannot enter boot camp! So you have to have perfect form and be in shape before you can enter boot camp!!
Now let me tell you, Powerlifting is much more technical than it appears. And Olympic lifting is even more so. This is just one of many reasons that Crossfit/boot camp is for the uneducated. No one that knows how to perform any of these training principles use them in conjunction with jump n jacks or incorrect rolling pull ups they think are difficult. Another point as you've heard me write about in the past in regards to my research is - when you consistently train the body at a high intensity level while mixing resistance with cardiovascular exercise, it's scientific fact you will burn muscle. The physical appearance is more related to diet than exercise. The way mitochondria are formed is the key to learning how it's also burned off. Basically the same way you build is the exact same way you lose.
Like joining the Army - skinny people gain a little muscle and fat people lean out. Same food. However, The Army figured it out. Do boot camp longer than 8 weeks and you will over train…no matter what age. In addition, you must be in shape before you start! It gets much, much deeper than this but for those who say they lost weight and feel great from that garbage… well, you lost muscle along with your weight and your waist will get thicker the longer you do it. Plus, your heart is a muscle and it will also eventually tear down too. Show me another sport on earth where every athlete in the competition is wearing "K Tape" by the time the comp is finished! You will have an injury soon... hang in there."